Microfluidic products with controlled fluid flow

Abstract

A microfluidic product utilizing gradient surface energy coatings for fluid control comprising a plurality of fluid passages wherein at least one fluid passage comprises a coating configured to control liquid flow wherein the coating configured to control liquid flow comprises a gradient surface energy coating from a proximal location to a distal location on a surface of the fluid passage. The product can include uniform regions and surface gradient regions in the same passage. Coating compositions and product dimensions can be selected to provide control over different flow properties including fluid velocity, reduction and acceleration of fluid flow, and starting and stopping fluid flow.

We claim: 
     
       1. A microfluidic product comprising an inlet port, a first detection region positioned downstream of a first fluid passage, and a second detection region positioned downstream of a second fluid passage, the first and second fluid passages each having a top surface and a bottom surface, wherein the first and second fluid passages each comprise a coating configured to control liquid flow on the top surface or the bottom surface wherein the coating configured to control liquid flow comprises a gradient surface energy coating from a proximal location on the top or bottom surface to a distal location on the top or bottom surface of the first and second fluid passages, wherein
 the inlet port is in fluid communication with the first and second detection regions, and 
 the gradient surface energy coating of the first and second fluid passages comprises species X1-J1-M1 and species X2-J2-M2 wherein X1, X2, M1, and M2 represent separate functional groups where M1 and M2 have different surface energies and J1 and J2 represents spacer moieties, and the molar concentration of the species X2-J2-M2 increases relative to the molar concentration of the species X1-J1-M1 in the gradient surface energy coating from the proximal location to the distal location. 
 
     
     
       2. The microfluidic product of  claim 1  wherein the first and second detection regions comprises one or more binding domains having immobilized binding reagents. 
     
     
       3. The microfluidic product of  claim 2  wherein the binding reagents comprise one or antibodies, proteins, receptors, ligands, haptens, or nucleic acids. 
     
     
       4. The microfluidic product of  claim 2  wherein the binding reagents comprise one or more electrochemiluminescent labels. 
     
     
       5. The microfluidic product of  claim 1  further comprising a pierceable container. 
     
     
       6. The microfluidic product of  claim 1  further comprising a reagent chamber for storing liquid reagents, the reagent chamber connected via one or more additional fluid passages to the first or second detection region. 
     
     
       7. The microfluidic product of  claim 1  wherein the coating configured to control liquid flow further comprises a therapeutic agent, a detection agent, a colorant, a biopolymer or combinations thereof. 
     
     
       8. The microfluidic product of  claim 1  wherein the composition of the gradient surface energy coating in the first fluid passage is different from the composition of the gradient surface energy coating in the second fluid passage. 
     
     
       9. The microfluidic product of  claim 1  wherein the top or bottom surface of the first or second fluid passage comprises a polymer material selected from the group consisting of polystyrene, polycarbonate, polyester, polyethylene, polyethylene terephthalate (PET), polyglycolic acid (PGA), polyolefin, poly-(pphenyleneterephthalamide), polyphosphazene, polypropylene, polytetrafluoroethylene, polyurethane, polyvinyl chloride, and polyacrylate (including polymethacrylate) and the functional groups X1 and X2 in species X1-J1-M1 and X2-J2-M2 comprise a photoreactive group. 
     
     
       10. The microfluidic product of  claim 1  wherein the top surface or bottom surface of the first or second fluid passage comprises a material selected from the group consisting of gold, silver, nickel, copper, aluminum, cadmium, zinc, palladium, platinum, mercury, lead, iron, chromium, manganese, tungsten, silicon, silicon oxide, and any alloys of the above and the functional groups X1 and X2 in species X1-J1-M1 and X2-J2-M2 are selected from the group consisting of thiols, sulfides, disulfides, silanes, and chlorosilanes. 
     
     
       11. The microfluidic product of  claim 1  wherein the first or second fluid passage further comprises a therapeutic agent, a detection agent, a colorant, a biopolymer or combinations thereof. 
     
     
       12. The microfluidic product of  claim 1  wherein the M2 species in the surface energy gradient coating of the first fluid passage is different from the M2 species in the surface energy gradient coating of the second fluid passage. 
     
     
       13. The microfluidic product of  claim 2  wherein the binding reagents comprise virus antibodies. 
     
     
       14. The microfluidic product of  claim 1  wherein the proximal location corresponds to the first or second fluid passage entrance and the distal location corresponds to the first or second fluid passage exit. 
     
     
       15. The microfluidic product of  claim 1  wherein the proximal location corresponds to a location on a surface of the first or second fluid passage that is downstream of the first or second fluid passage entrance. 
     
     
       16. The microfluidic product of  claim 1  wherein the distal location corresponds to a location on the surface of the first or second fluid passage upstream of the first or second fluid passage exit. 
     
     
       17. The microfluidic product of  claim 1  further comprising a fluid passage that is not coated. 
     
     
       18. The microfluidic product of  claim 1  further comprising a third detection region wherein the third detection region is used in a control/calibration for measuring assay control/calibration samples. 
     
     
       19. The microfluidic product of  claim 1  wherein the microfluidic product comprises an assay cartridge used to carry out panels of assays. 
     
     
       20. The microfluidic product of  claim 19  wherein the assay comprises virus antibodies.